I'm a little confused. During Beta(-) radiation, a neutron becomes a proton due to a down quark becoming an up quark. When this happens, a W(-) boson is emitted which almost immediately decays into an electron and an electron antineutrino. A W(+) boson, similarly, is emitted when a down quark turns into an up quark and decays into a positron and an electron neutrino. If a W boson is an elementary particle, how does it decay into these? Thanks, guys! It's a huge help!